Study on Preparing Isolongifolene from Longifolene Catalyzed by Solid Superacid

By LUO Jin­yue 1， AN Xin­nan 1， LEI Fu­hou 2

（1. College  of  Chemical  Engineering,Nanjing  Forestry  University,  Nanjing  210037, China；2. College of Chemistry and Ecology Engineering，Guangxi University for Nationalities， Nanning 530006，China)

Abstract: The reactions of　isomerization of longifolene catalyzed by SO42-/TiO2ZrO2 solid superacid are performed. From analyses of GC and GC­MS, the main product is isolongifolene from isomerization. The result shows that this catalyst has a high catalytic activity and a good selectivity to isomerization of longifolene. The factors affecting its catalytic activity are investigated. The result also shows that the optimum conditions for the preparation of SO42-/TiO2ZrO2 catalysts are as follows: n(Ti)∶n(Zr)　3∶1, and calcination temperature 550 ℃. Under these conditions, the optimum conditions for isomerization of longifolene are as follows: reaction time 4 h, isomerization temperature 165 ℃, and ratio of solid superacid to longifolene mass part 4 %. Under these conditions, the conversion of longifolene is 99.1 %, and the yield of isolongifolene is 97.2 %. Furthermore,experiments on the  effect of storage time of the catalysts on the reaction and the regeneration of catalysts are carried out.
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Key words:  longifolene；isolongifolene；solid superacid；SO42-/TiO2ZrO2 catalyst